samples/kprobes: Add ARM support

Plenty of architectures are already supported and this adds ARM
support.

Signed-off-by: Marc Koderer <marc@koderer.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210112154054.17138-1-marc@koderer.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>